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Abstract:

An intrauterine device for delivering bioactive substances in the uterine
cavity includes a plastic frame affixed to a drug delivery compartment.
In use, the frame retains the IUD in the uterine cavity and prevents
displacement and expulsion. The frame is shaped like the letter "omega"
having two resilient arms which possess latero-lateral memory. The
extremities of the arms are provided by a short side-arm which forms an
angle with the rest of the arm. These prominent plastic parts facilitate
the upward rotation of the arms during removal of the intrauterine
device. Due to the resilience of the arms, the frame adapts to cavities
of every size, maximizing tolerance. The drug delivery compartment has an
element at its upper extremity to determine the exact location of the IUD
in the uterine cavity by ultrasound. The drug delivery compartment
contains one or more drugs which are gradually released in the uterine
cavity over extended periods of time.

Claims:

1-14. (canceled)

15. An intrauterine device (IUD) comprising: a curved plastic frame and,
a substantially straight compartment adapted to deliver at least one
bioactive substance, whereby said curved plastic frame is sufficiently
resilient and extendable to allow adaptation to various sizes and shapes
of the uterus, and adapted to be easily assembled, and securely fixed, to
said straight compartment through a transversal hole provided in an upper
extremity of the straight element, the assembly enabling pivoting of said
frame within said hole when a traction is exerted on the lower end of the
straight compartment to allow its easy removal wherein the ends of the
curved plastic frame comprise each a protruding element extending
outwardly.

16. A IUD according to claim 15 wherein the protruding elements are
elongated elements whose directions form an angle alpha of 45.degree. to
90.degree. with the straight compartment.

17. An IUD according to claim 15 wherein the protruding elements are
straight extending elements.

18. An IUD according to claim 15 wherein the protruding elements are
essentially perpendicular to said straight compartment.

19. An IUD according to claim 15 wherein the median part of the plastic
frame comprises a section of narrower diameter.

20. An IUD according to claim 15 wherein the median part of the plastic
frame consists of a straight section.

21. An IUD according to claim 15 wherein the protruding elements
extending outwardly define an axis of rotation (b) of the curved plastic
frame while such is pivoting in the hole of the straight compartment when
traction is exerted downwardly for removal.

22. An IUD according to claim 15 wherein the substantially straight
compartment is a drug delivery rod having a dome-shaped tip, for
facilitating the insertion of the IUD in the uterus.

23. An IUD according to claim 22 wherein at least one end of the drug
delivery rod consists of denser material than the middle section of the
drug delivery rod.

24. An IUD according to claim 15 wherein the drug delivery compartment
has a diameter between 2 and 3.5 mm.

25. An IUD according to claim 1, wherein the outwardly extending elements
are 2 to 5 mm long.

26. An IUD according to claim 15, wherein the compartment is 25 to 40 mm
long.

27. An IUD according to claim 15 wherein the device is a contraceptive
device.

28. An IUD according to claim 15 wherein the device is suitable for
gynaecological treatment.

Description:

FIELD AND BACKGROUND OF THE INVENTION

[0001] Intrauterine drug delivery is becoming increasingly important in
gynecological practice. Intrauterine drug delivery can be used for
contraception and treatment of various gynecological conditions. However,
with existing intrauterine systems, delivering hormones in the uterus,
there are several drawbacks which can be improved such as the ease of
insertion in the uterine cavity, adaptation of the plastic frame to
different sizes and shapes of uterine cavities to minimize side effects,
retention of the IUD in the uterus, retrieval of the intrauterine foreign
body from the uterus and visibility of the body on ultrasound
examination.

[0002] The plastic frame of intrauterine devices (IUD) often creates
dimensional incompatibility with the uterine cavity which could give rise
to complaints such as abnormal uterine bleeding and cramping pain.
Incompatibility also leads to displacement and expulsion of the IUD.

[0003] In an attempt to improve compatibility with uterine cavities of
different sizes and shapes, and avoid expulsion and translocation, the
"Multiload®" IUD (Organon) was created wherein the arms are
approximately in the shape of the letter "omega" (see U.S. Pat. No.
3,952,734) and comprise lateral extensions. However, although the curved
arms can adapt to the width of various uterine cavities, the arms are not
enough resilient and, therefore, downward displacement of the IUD is not
prevented by the design characteristics of the IUD. The arms of the
Multiload® IUD also form an integral part of the plastic frame and
cannot rotate during retrieval of the device from the uterine cavity.
Removal of the Multiload IUD® requested by the woman is therefore
sometimes difficult, painful and could also damage the uterus. One or
both arms could also break off during removal of the device which can
lead to complications.

[0004] Ultrasound examination has become routine in gynecological
practice. The proper performance of the IUD is related to the proper
position of the IUD in the uterine cavity. The assessment of the proper
location of an intrauterine system in the uterine cavity by ultrasound
which does not contain a metal such as copper is sometimes difficult,
especially if there are uterine abnormalities.

[0005] To enhance the visibility of the drug-releasing IUD on ultrasound,
the development of simple means will facilitate the location of the
device in the uterine cavity. This can be accomplished by increasing the
density of a part of the drug delivery compartment. The best way to
assess the proper location of the IUD in the uterine cavity is by
measuring the distance between the outer and upper surface of the uterus
and the upper extremity of the drug delivery compartment. The more denser
part of the drug delivery rod should therefore be selected to make it
denser and more visible on ultrasound.

[0006] Another important aspect is the assembly of the plastic frame with
the drug delivery compartment. The assembly of a plastic component which
has multiple curves, with the rod-shaped drug delivery compartment is not
evident. First, from a manufacturing point of view it is important that
the plastic part can easily be assembled with the drug delivery rod.
Therefore, the plastic frame should be resilient to allow straightening
of the curves. The frame should not be provided with hooks or prongs such
as those provided in the Multiload® IUD which would prevent the
assembly with the drug delivery compartment. Secondly, it should be so
constructed that its acts as a proper retaining member and,
simultaneously, allows adaptation to the great differences in width of
uterine cavities and thirdly, the assembly should allow easy upward
rotation of the plastic frame during caudal traction on the IUD to allow
easy removal of the IUD from the uterine cavity.

[0007] The aim of the present invention is to optimize intrauterine drug
delivery to facilitate insertion, enhance acceptability and tolerance,
improve retention, facilitate or even make removal possible and enhance
visibility by ultrasound to allow assessment of the proper positioning of
the IUD in the uterine cavity. To this end, the present invention
concerns the design of a new platform for the delivery of drug(s) in the
uterus for contraceptive and treatment purposes, easy to insert and
remarkable well tolerated by parous, nulligravid/nulliparous women and
women in the postmenopausal phase which have uteri which markedly differ
in size and shape and are usually very small.

[0008] The present invention constitutes also an improvement of the
intrauterine device disclosed in WO 03/068117 or U.S. Pat. No. 7,080,647
B2, these latter documents being incorporated herein by reference.

SUMMARY OF THE INVENTION

[0009] According to the present invention, a drug delivery platform is
provided of which the plastic frame is approximately omega-shaped or
partly oval-shaped when placed in the uterine cavity, the arms of which
are resilient in latero-lateral direction and which allow adaptation and
retention in uterine cavities of different size and shape and of which
the plastic frame can easily be assembled with a straight drug delivery
rod. An additional aim of the present invention is to provide a plastic
frame which is provided with a means to allow easy upward rotation of the
arms during removal of the IUD.

[0010] A further aim of the invention is to enhance the visibility of the
IUD on ultrasound.

[0011] These goals are reached, according to the present invention, by
providing an IUD which consists mainly of two parts:--the stem of the IUD
which is the drug delivery compartment, or rod--and the plastic frame or
retaining member of the IUD. The drug delivery compartment contains the
active pharmaceutical ingredient (API), which can be a hormone, or any
other chemical substance, and which functions as vertical stem of the
IUD, and is lying in the longitudinal axis of the uterine cavity. The
loaded drug delivery rod consists preferably of a polymer which is
sufficiently resilient to prevent damage of the uterine wall during use
of the IUD and adapts to the curvature of the uterine cavity. The plastic
frame, according to the invention comprises two curved arms,
approximately "omega" shaped, when located in the uterus and consists of
a material which is sufficiently resilient to adapt to uterine cavities
which differs in size and shape and which exerts latero-lateral pressure
on the uterine wall to enhance retention of the IUD in the uterine
cavity. Material of the plastic frame part may be any biocompatible
resilient plastic, for example polyethylene. The plastic frame, according
to the invention can be straightened in order to allow its insertion and
fixation through a hole made in the upper part of the drug delivery rod.
The plastic frame lies in the upper part of the uterine cavity and is
held in position by the stem of the IUD, being the drug delivery
component.

[0012] According to another characteristic of the invention, the arms of
the plastic frame can adapt to cavities of every size and shape by
approximation and exert lateral pressure on the side walls of the uterine
cavity.

[0013] According to an additional characteristic of the invention, the
plastic frame is provided with a narrow part in the middle which, at
assembly with the drug delivery rod, is the part that is connected with
the upper part of the drug delivery compartment. This stabilizes the
assembly and reduces the frictional force. It facilitates the rotation of
the plastic part within the hole of the compartment when.

[0014] According to yet another characteristic of the invention, the tips
of the arms of the omega-shaped plastic frame are curved forming an angle
of at least 45° with the main body of the frame. Preferably the
angle is above 80°, still preferably 90°.

[0015] According to yet another characteristic of the invention, the
plastic frame is able to rotate in anterior or posterior direction, along
an axis formed by the connecting hole in the upper part of the drug
delivery rod, when traction is exerted on its lower end to remove the IUD
from the uterine cavity.

[0016] According to another characteristic of the invention, the drug
delivery compartment, at its upper and lower extremity, is denser in
composition than the rest of the drug delivery rod.

[0017] According to another characteristic of the invention, the ends of
the drug delivery rod are rounded off or dome shaped to facilitate
insertion of the IUD in the uterine cavity.

[0018] According to yet another characteristic of the invention, the drug
delivery compartment is between 2 and 4 cm long.

[0019] According to an additional characteristic of the invention, a small
hole is provided in the lower part of the drug delivery compartment to
allow the tying of a removal thread.

[0020] According to another aspect of the invention during the
manufacturing phase, the plastic frame is introduced by one of its ends
in the hole provided in the upper part of the compartment element. This
may be made by force. The flexibility and the diameter of the linear
plastic frame should therefore be appropriate in this regard. In
particular, the diameter along the plastic arms should be adapted to
permit the sliding inside the hole. The diameter may vary from the end up
to the mid-section of the omega-shaped plastic member.

DESCRIPTION OF THE DRAWINGS

[0021] These and other characteristics of the invention will be more
readily understood when referring to the description as well as the
accompanying drawings which represent, merely by way of examples, several
embodiments of the invention, and in which:

[0022] FIGS. 1a and 1b represent in a very schematic way a preferred
embodiment of an IUD according to the invention, showing the two parts of
the IUD: the curved shaped part 2 and the straight drug delivery rod 1,

[0023] FIG. 2 is a schematic cross sectional view of the uterus with a
preferred embodiment of an IUD according to the invention, showing the
possibility of adaptation of the plastic frame according to different
widths of uterine cavities.

[0024]FIG. 3 is another schematic cross sectional view through the
connection of the two elements of the IUD showing the narrow part 3 of
the plastic frame when assembled in the hole made in the upper part of
the drug delivery rod and along which the plastic part can rotate,

[0025]FIG. 4 represents another schematic cross sectional view of the
uterus with a preferred embodiment of an IUD according to the invention
showing rotation of the plastic frame, during removal of the IUD from the
uterine cavity, around an axis through the narrow part of the plastic
frame of the IUD. The presence of small plastic ends of the arms which
form an angle with the body of the plastic frame allows the rotation to
take place.

[0026]FIG. 5 represents another schematic cross sectional view of the
upper and lower denser ends of the drug delivery rod and the rounding of
the tips.

[0027]FIG. 6 is a view of the plastic frame according to the invention in
both relaxed configuration and folded configuration.

DETAILED DESCRIPTION

[0028] Referring now particularly to FIGS. 1a and 1b, the IUD according to
a embodiment of the invention is illustrated respectively in the relaxed
state and in the folded state. The IUD consists essentially of a plastic
frame 2 made in a material which is resilient, and a drug delivery
compartment 1 also made in a material which is resilient and flexible.
The mid-section of the plastic frame is connected with the drug delivery
rod 1 through a hole 4 in the its upper part forming an assembly which is
easily inserted in the uterus with a hollow tube (e) when the drug
delivery rod is inserted in the tube. Also illustrated are small ends 6
of the arms of the plastic frame, extending outwardly. These elements due
to the resilience of the arms are in contact of the wall of the uterus.

[0029] According to the representation in FIG. 2, the plastic frame 2
allows approximation of the arms of the frame to adapt to different
widths of uterine cavities. If the uterus is wider, the plastic frame 2
extends laterally to make contact with the uterine wall on both sides to
maximize retention of the IUD in the uterine cavity. During insertion of
the IUD in the uterine cavity, the arms 2a and 2b fold and the memory of
plastic will adjust the arms to the width of the uterine cavity.

[0030] According to FIG. 3, the plastic frame 2 has a narrow part 3 in its
middle section for the fixation of the frame in hole 4 of the drug
delivery rod 1 which prevents frictionally easy dislodgement of the two
parts.

[0031] According to FIG. 4, the plastic frame 2 "pivots" around its axis
"a" which is formed by the connection of the narrow part 3 and the hole 4
in the drug delivery rod 1 when caudal traction is exerted on the tail or
thread 5 which is connected to the lower end of the drug delivery
compartment 1. According to the invention the small ends 6 facilitate
rotation, forming an axis of rotation "b" of the device at least during
the initial withdrawing movement as shown in FIG. 5.

[0032] The denser tips (7a and 7b) of the drug delivery rod increase the
visibility of the IUD by ultrasound examination.

[0033]FIG. 6 is an enlarged view of the plastic frame according to the
invention in both relaxed configuration and folded configuration. The
frame has an essentially semi-oval shape, with however arms having a near
straight section A.

[0034] Typically the radius of the upper curvature is 4-5 mm and of the
near straight section 35-45 mm. Diameter of the arms is around 1.6 mm and
diameter at the medial straight, which is around 2.4 mm long, is narrower
by 2 mm. The elements 6 are 3 mm long and their ends are rounded.

[0035] The invention has been described and illustrated merely by way of
examples which are in no way restrictive. Numerous changes in its
conception may be made without departing from the scope of the invention
as defined in the attached claims.